This topic was beaten to death a few months ago so if you use the search function. Specify this form, pic threads, and search for recommendations. That will give you a lot more information than your thread will probably get but here is my take on you situation.
1) User your former sup as one definitely. Thats their second most desirable person to do a rec behind a current supervisor.
2) A common question of recommenders is their interactions with you. So if he can say he interacts with you on a near daily basis he will work.
DO NOT use a co-worker unless you absolutely had to. Its a terrible idea, unless the school asks for a peer recommendation.
Since you aren't using a current supervisor, most schools will want to know why you didn't get one from him/her. So you need a good reason, that way they don't think its because you thought they wouldn't give you a good rec.
Make sure you give your recommenders the forms, and some info on why you want an MBA, future career goals...you want to walk them through the process.